A key management issue for interoperability between private and public clouds is that there are several business-level IT management systems that fundamentally break when you interoperate; chief among them back-up and recovery, Melbourne IT’s CTO, Glenn Gore, says.
“If you back up a virtual machine in your own private cloud then move it out from your private data centre out into the public cloud the entire backup methodology breaks,” he says. “You also don’t want to backup from the public cloud back into your private cloud as it will kill you in terms of band width costs and will not perform well. If you use your hosting provider’s back up service it will be a different client with a different regime.”
The difficulty in wrapping meta data around virtual machines (VMs) in the cloud means that, when it comes to moving cloud providers, describing the security posture of VMs becomes an issue. IT managers should therefore detail which VMs should be backed up, how often they’re backed up and how often.
Move from provider A to B and C, and each of provider will have a copy of backup data. Requirements should consequently detail whether providers must destroy the data or keep it for a nominated period. How will you ship every copy of that data on to the new cloud provider from the last one?
“You may also start with a 50 gig virtual machine, but once you start shipping it around it may grow to a terabyte or two, with six months worth of change histories being imported and exported between providers,” Gore says.
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